Lamp-socket.



' A. C. McWILLIAMS.

LAMP SOCKET. APPLICATION FILED APR..I4. I916.

Patented Apr. 10, 1917.

2 SHEETFSHEET I.

- muwu A. c. McWlLLlAMS.'

LAMP SOCKET.

.PPLICATION FILED APR. 14, 1916.

Patented Apr. 10, 1917 2 SHEETS-SHEET 2.

ARTHUR C. McWILLIAMS, OF CHICAGO, ILLINOIS.

' LAMP-SOCKET.

. Specification of Letters Patent.

Patented Apr. 10, 1917.

Application filed April 14, 1916. Serial No. 91,016.

To all whom it may concern:

Be it known that I, ARTHUR C. NIQVVIL- mans, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Lamp-Sockets, of which the following is a specification.

My invention relates to devices of the class sometimes referred to as film sockets for series incandescent electric lighting. Various attempts have been made to obtain a safe,

dependable, compare and easily operated device of this character, but the devices heretofore made have left much to be desired in some 11 not all of these particulars: Furi -the invention will become more apparent as the description proceeds, it may be stated in general that the objects of the invention are; first, to reduce the aggregate size of the parts which constitute the filmholder; second, to render the film holder practically invisible when the lamp and film holder are in place in the base or socket and quite in visible when the usual. shade and reflector is in place; third, to enable the film holder to be introduced to the socket through an opening in the reflector but little larger than the opening required for the lamp base; fourth, to render the film holder practically a part of the lamp; fifth. to make it possible and practicable to manipulate the film holder through the agency of the lamp itself-and even from theouter end of .the lamp; sixth, to dispense with the need for porcelain, vulcanite or other insulating body of considerable size upon the film holder; seventh, to

obtain uniform pressure on the film, and to make the intensity of the pressure qulte independent of the degree to which the operator screws the parts into the base or socket,

eighth. to make it practicable to use dupli (ate for replacing the films; tenth, to accomplish these things in connection with a screw socket in distinction to a push socket.

I accomplish my objects by the mechanism illustrated in theaccompanying drawings, in which i I Figure l is a side elevation of a nitrogen films ninth. to simplify the procedure or gas filled tungsten lamp equipped with my film holder and in position within the lamp base. The figure also shows, partly in section and partly in side elevation, the shade and refiector, best adapted for this particular style of lamp. Fig. 2 is an assembly view, chiefly in axial section of asocket and film holder embodying my invention. The lamp is shown. in position.

Fig. 8 is an axial section of the socket showing the short circuiting switch closed.

Fig. 4 is an axial section of the film holder with a lamp in position in it.

Fig. 5 is a perspective view of the parts shown in Fig. 2, the porcelain being removed and some of the metal parts broken away to better reveal the construction.

Fig. 6 is a perspective. view illustrating the method of manipulating the film holding spring. I Fig. 7 1s a view of the socket looking d1- rectly thereinto.

Fig. 8 is a detailsection showing one manner of constructing certain parts of the film. holder.

Similar numerals refer to similar parts throughout the'several views.

In the form selected to illustrate the invention, the base 1, which is usually. of porcelain, contains a metallic shell 2 which is in.- teriorly threaded for receiving the shell 3 of the film holder.. The base and its shell 2 may be considered as constituting a screw socket and the shell 3 of the film holder is internally and externally threaded so that it may screw into shell 2 and the lamp ma) screw into it. spring switch 4- is located within the screw socket and when the lamp is absent engages the inner end of the shell 2 as shown in Fig. 3. A post 5 of conductive material is fastened to switch a, at the center otthe socket in position to be en gaged and pushed back to open the switch when the lamp is introduced into the socket. This condition is illustrated in Fig. 2. The parts. i and 5 may be regarded as forming the center contact of the socket. The base 1 is provided with suitable terminals, one of which is in electric connection with the shell 2 and the other with the spring switch 4. In the particular construction illustrated, these terminals consist of binding posts 6, 6, provided with binding screws 7, 7, and connected by conducting strips 8, 8 and (all screws 9, 9 to the shell 2 and spring switch 4 respectively, as shown in perspective in v Fig. 5.

The lamp 12 has at the base the usual center contact 13 and outer contact or collar 1%, these constituting the two terminals of the lamp. Fig. 1 of the drawings shows a gas filled lamp wherein the filament 15 is short and located near the outer end of the lamp. While my invention is useful in connection with any of the standard types of incandescent lamps, it is eminently fitted and advantageous for use in connection with a lamp of the character shown in Fig. 1 for reasons which will hereinafter appear.

Tn Figs. 4 and 6 the parts which constitute the film holder are shown separately except for the presence of the lamp. lln the particular configuration illustrated, the me tallic shell 3 has a flange 17 at its inner end extending toward the center. Rising from this flange are two posts 18, 18,the parts 3, 17 and 18 being preferably integral with each other and the posts being preferably arranged diametrically opposite to each other.

The film holder is provided with a'center contact 20, which, when the parts are assembled, overlies the center contact 13 of the lamp and engages it on the one side and the post 5 on the other side. Contact 20 has an arm 21 extending from one side thereof, this being turned up at the end and there riveted or otherwise fastened to the film holding spring :22 as shown in detail in Fig. 8. The center contact is fastened to the flange 17 by means of a screw 23 or otherwise, and is insulated from said flange by a layer 24 of insulating material thus, the center contact 20 and spring 22 are fastened to the shell 3 of the film holder but are insulated from it. The arm 21 and contact 20 are preferably ofa single piece of comparatively thin sheet metal so as to be flexible to a sufficient ex- 45 tent to permit the parts to accommodate themselves to different positions-of the coacting parts. The spring 22 is approximately U-shaped, the ends 26 bending slightly outward whereby they may be conveniently grasped between the thumb and finger of the operator, as suggested in Fig. (i. This spring is attached midway between its ends to the arm 21 of the center contact 20 and presses outward toward the posts 13 formed on shell 3. Between the spring and each of the posts 18 is a piece 27 of dielectric material which is disruptible when the impressed voltage exceeds a predetermined maximum. For convenience, these 80 elements 17 may be termedv the films. They normally insulate the spring from the posts 18 of the shell 3, but in case of excessive voltage or surging on. the lines, these films break down and permit electric con- 65 motion between the spring and the posts.

The shell 3 is designed to be securely fastened to the base of the lamp and while the fastening means may be varied, I prefer to use a clamp ring 30, the ends of which are tightened or loosened by means of a clamp screw 31 as shown in perspective in Figs. 5 and 6. This ring is preferably located at the end of the shell opposite tothe center contact 20 as a result of which the clamping ring comes just beyond the outer end of the socket shell 2 when the lamp is screwed home. A suitable proportioning of the parts is suggested in Fig. 2 of the drawin s. I cut a slot 32' for a certain distance into t e shell 3 so that the outer end of the shell may be contractible and eXpansible and permit the clamping ring to clamp the shell 3 and other parts of the film holder firmly to the base of the lamp and remain there while the lamp is being unscrewed and removed from the socket.

Referring to Fig. 1, the base or socket is shown fastened to a bracket 35 which sup ports a shade 36 of the type usually employed in outdoor lighting. A reflector 37 is mounted within the shade and has a center opening 38 which is not much larger in diameter than the base of the lamp. It will be noted that the reflector comes down at the center to a point approximately mid way between the ends of the lamp. This is to properly distribute the light from a lamp of thegas filled type Where the filament is cpncentrated near the end of the lamp.

In using the device of my invention the operator screws the shell 3 down on to the threaded base of the lamp until the center contact 20 of the film holder makes close engagement with the center contact 13 of the lamp. He then tightens the screw 31 which firmly clamps the device in place upon the lamp so that the lamp and the film holder operate practically as a single thing. The film holder thus practically becomes a part of the lamp in the sense that the lamp and the film holder may be inserted as a unit into the socket and maybe withdrawn therefrom without requiring the operator to touch anything but the lamp itself in the manner suggested in Fig. 1. "When the film holder has been thus applied and securely fastened to the lamp, the operator inspects the films to see if they are intact. If they need renewing, he pinches the free ends of the spring 22 together to thereby cause the sides of the spring to withdraw from the posts 18 sufficiently to remove the old films and supply new ones. As soon as the new films are in place the operator releases the ends of the spring whereupon it expands and presses the films against the posts thereby holding said films securely in place. The

device is then ready to be inserted into the socket. Thereupon the operator grasps the outer end of the lamp and if the socket is mounted within a shade and reflector of the general type shown in Fig. 1, the operator will pass the base of the lamp with the fi m holder thereon up through the center opening 38 of the reflector 37 until the film holder reaches the socket, whereupon the operator will screw the lamp home into the socket. As the lamp and film holder are about to reach final position, the center contact 20 of the film. holder engages the center [st and pushes the short circuiting switch l to open position, as shown in Fig. 2. This puts the lamp in circuit. It,'now, the lamp burns out or there is excessive voltage on the line from any cause whatever, one or both of the lilms 27 will, become disrupted or punctured and permit the current to flow directly from the spring 22 to one or both of the posts 18. This shunts the current around the lamp and enables it to flowtrom one of the binding posts 6 to the other. As

the lamp is now out of commission, the operator when he arrives, grasps the projecting end of the lamp and rotates it in a direction tounscrew it, but the film'holder, being fastened to the lamp, instead of remaining in the socket comes with the lamp. If, upon inspection, the operator finds that the lamp itself is still intact, he simply pinches the ends of the spring together, removes the oldfilms and substitutes new ones. If it be found that the lamp is damaged, the operator backs off the clamp screw 31, thus loosening the clamping ring and making it possible for him to unscrew the film holder from the base of the lamp. The advantages resulting from this construction are very important; In the first place, as the film holder becomes in certain respects a part of or a fixed attachment to the lamp,

it becomes possible to insert or withdraw the film holder into and from a socket, Wl11Cl1,. when mounted as in Fig. 1, would be quite out of reach. My construction insures that the film holder will leave the socket instead of permitting the lamp to leave the film holder, the same being accomplished to a certainty in a screw socket in distinction to a push socket. Another advantage resulting from the ability of the device to be manipulated by grasping the lamp only, is that it sa'leguardsthe operator when working under adverse weather conditions. Glass is an efiicient insulator, but has the special advantage that water does not collect upon it in sheets but in drops. for the operator, even in wet weather. to unscrew the lamp without opening the circuit through the linc---a thing which is to be avoided, if possible, in series lighting. Another important result is that the pressure upon the films is quite independent of the force with which the operator screws the lamp into the socket. The voltage at which films will puncture depends, very.

I film holder.

This makes it safelargely, upon the compression to which they are subjectedfthe greater the pressure the lower the voltage, and vice versa. With the new gas filled lamps, it is important that the puncture point should be controlled with considerable accuracy, for in these lamps the filaments are operated at a much higher temperature and therefore much morenearly at the melting point of the filament than is the ease with the ordinary tungsten lamp or withthe carbon filament lamp, Consequently, there is a smaller practical range of operation afforded. In my construction the pressure upon the filaments is regulated entirely by the film holding spring and this'is in nowise affected by the force employed by the operator in screwing home the lamp. Again my device occupies but small space, and intact, the lamp and socket parts are practically no larger when constructed to accommodate my film' holder than they would be it they were designed to omit my Incidentally, this renders the film holder, if not invisible, at least nearly so, as will be evident by a reference to Fig. 1 of the drawings. The total diameter of the film holder is but little larger than the diameter of the base of the lamp.

, Having thus described my invention, what I claim as ne Y and desire to secure by Let ters Patent, is:

1. For use in series electric lighting, the combination of a metallic shell having an external thread for screwing into a lighting socket, said shell being adapted to make electric connection with the outer terminal of an electric lamp, :1 center contact for engaging the center terminal of the lamp, said center contact being'fastened to but insulated from the shell, and a spring pressing toward a part of said shell for holding a dielectric in position, the spring being in electric connection with said center contact, and said spring, when the parts are assembled, being free from the adjacent parts of the device.

2. In a device of the class described, a shell screwing into a lighting socket, a center contact fastened to but insulated from said sl ell,a spring electrically connected to said center contact and pressing toward some part of said shell for holding a dielectric, and means for, securely attaching the shell to the base of' an incandescent electric lamp whereby the shell. and parts attached thereto may be unscrewed from the socket by rotatively mani )ulating the lamp only.

In a evice of the class described, a metallic shell having an external thread for screwing into a lightingsocket. a clamp for securely attaching the shell to the base of an electric lamp whereby the shell may be unscrewed from the socket by grasping the lamp and impartinga rotary mo ement the lamp is in place in the shell, a center contact fastened to but insulated from said shell, for engaging the center contact of the lamp, and a spring fastened to but insulated from said shell, the free portion of the spring ressing radially outward toward some portion of the shell for holding a dielectric in position. i

4. In a device for electric lighting, an externally threaded shell for receiving the base of the lamp, said shell screwing into the lighting socket and being in electric connection with the outer contact of the lamp when the lamp is in place, a center contact mount- 7 ed on but insulated from said shell, said center contact engaging the center contact of the lamp when the latter is in place, a dielectric, a backing for said dielectric, and a spring for exerting constant pressure upon said dielectric to press it against its backing, said spring and the backing being electrically connected, one to the shell and the other to the first mentioned center contact.

5. In a device for series electric lighting, a shell for receiving the base of the lamp, said shell having anexternal thread for screwing into a lighting socket and being in electric connection with the outer contact of the lamp when the lamp is in place, a center contact mounted on but insulated from said shell, saidcenter contact engaging the center contact of the lamp when the latter is in place, a dielectric, a backing for said dielectric, and a spring for exerting constant pressure upon said dielectric. to press it against its backing, said spring and the backing being electrically connected, one to the shellv and the other to the first mentioned center contact, said spring being free of surrounding objects when the parts are assembled, whereby it may exert uniform pressure upon the dielectric regardless of the position of the lamp in the shell or of the shell in the socket.

6. In a device for series electric lighting, a metallic shell externally threaded for screwing into a lighting socket, said shell being also internally threaded to be screwed on to the base of the lamp, and having a surface provided for backing up a dielectric film, a center contact for engaging the center terminal of the lamp, and a spring fastened to but insulated from the shell and electrically connected to said center contact, said spring being in position to press against the surface provided on the shell for back ing up the film.

7. In a devicefor electric lighting, a metallic shell externally threaded for screwing into a lighting socket, said shell being internally threaded to be screwed on to the base of the lamp, the shell being open at the inner end and having a surface provided for backing up a dielectric film, a center contact for engaging the center terminal of the a metallic shell having an external thread for screwing into a lighting socket, said shell being adapted to be screwed on to the base of the lamp, the shell being open at the inner end and having a surface provided for backing up a dielectric film, a center contact forengaging the center terminal of the lamp, and a curved spring bordering the opening at the inner end of the shell and being fastened at one point to the shell but insulated therefrom, said spring being electrically connected to the center contact and pressing radially outward toward the surface provided on the shell for backing up the film.

9. In a device for series electric lighting, a metallic shell having an external thread for screwing into a lamp socket, said shell being adaptedto be screwed onto the base of the lamp, the shell being open at the inner end and having two upstanding posts at the inner end forbacking up dielectric films, said posts being arranged on opposite sides of the center contact being in electric connection with said spring.

10. In a device for electric lighting, a metallic shell having an external thread for screwing into a lamp socket, said shell being adapted to be screwed on to the base of the lamp, and having an opening at the inner end, said shell having two, upstanding posts at the inner end for backing up dielectric films, said posts being located on opposite sides of the opening at the inner end of the shell, an approximately 'U-shaped spring encircling the opening-at the inner end of the shell and fastened between'its ends to the shell but insulated therefrom, said spring being. bent at the free ends to enable the ends to be pinched together to release the films, the spring pressing radially outward toward the posts for holding the films, and a center contact electrically-connected to the spring and located in position to engage the center terminal of the lamp when the parts are assembled.

11. For use in electric lighting, an externally threaded shell for screwing into a threaded lighting socket, said shell being adapted to receive the base of an electric .U-ting semifinals carrier by if said t mils being 'reits awn force, a di said ten? is, one 0f said insulatefi. Join the shell, electric ccnnecticn with the. E1315; being in electric connecres'nective lamp terminals is in place in said sheil, and

.501 securing the shell to the '11 externally threacle meig an. external fihread for lighting socket, said shell 6. to make electric connection series electric lig'litin the with the outer terminal of an electric lamp,

.a center contact fer'engaging the centei terminal of the lamp, said cenfier contact being fastened te but msulated from the 0 shell, .1 spring pressing towari some portion 0f said shell for iolding a dielectric in position, the spring beingin electric connection with said center contact, and said sprin when the parts are assembled, being 25 free one the adjacent parts of the device,

and a clamping ring for securing the shell to the lamp base.

In witnew whereof, 1

scribed my name ARTHUR C. MGWVILLIAMS.

have hereunto sub- Copies "I: this patent may be obtained fer five cents each, by addressing the Commissioner of Patents,

' Washington, D. G. 

